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Notes: Haematological indices were obtained by Coulter Counter analysis from 325 women in the first stage of labour, and from the cord blood of their newborn babies. The mean maternal haemoglobin concentration was 12·49 g/dl and the mean cord haemoglobin 16·18 g/dl. The mean corpuscular volume measured directly was 89·00 fl from maternal blood and 106·73 fl from the cord blood; the two ranges barely overlapped and it should be possible by automated analysis to differentiate between fetal and maternal blood obtained at amniocentesis or artificial rupture of the membranes at term.

Notes: Plant-pathogenic nematodes are a major cause of crop damage worldwide, the current chemical nematicides cause environmental damage, but alternatives such as biological control are less effective, so further understanding of the relationship between nematodes, nematicides, biological control agents and soil and rhizosphere microorganisms is needed.Microbial populations from roots of cabbage and tomato plants infested with the root-knot nematode Meloidogyne incognita were compared with those from plants where the nematode was controlled by the nematicide aldicarb, or a nematophagous fungus with biological control potential, Pochonia chlamydosporia. The total numbers of culturable bacteria and fungi in rhizosphere soil were similar in all three treatments for both plants, around 100-fold more than in control soil in which there were no plants. However, there were clear differences in the catabolic diversity, assessed by Biolog EcoPlate™ carbon substrate utilization assays, between microbial populations from unplanted soil and the rhizosphere. In cabbage, a poor host for M. incognita, the rhizosphere population from P. chlamydosporia-treated plants was distinct from the population from untreated and aldicarb-treated plants. In tomato, a host susceptible to the nematode, the catabolic diversity of populations from aldicarb- and P. chlamydosporia-treated plants was similar and differed from the untreated, nematode-infested plants. The genetic diversity of the fast-growing heterotrophic bacteria in the tomato rhizosphere, indicated by PCR fingerprinting with ERIC primers, was very different in the infested roots, whereas the profiles of isolates from both aldicarb- and P. chlamydosporia-treated roots were similar. Evidently, nematodes have a greater impact on the rhizosphere population of a susceptible host, tomato, than a poor one, cabbage, and nematode-infested roots are colonized by a different subpopulation of soil microbes from that on plants where infection is controlled, illustrating differences in root morphology and physiology.

Notes: The effects of past applications of farmyard manure (FYM, applied from 1942 to 1967), metal-contaminated sewage sludge (applied from 1942 to 1961) and mineral fertilizer (NPK, applied from 1942 until now) on the microbial biomass and community structure in a sandy loam, arable soil from the Woburn Market Garden Experiment, UK, were investigated in 1998. Concentrations of Cu, Ni and Zn in soils which previously received sewage sludge were less than current European Union (EU) limits, but the soil Cd concentration was more than twice the permitted limit. Organic-C concentration in the FYM-treated soil and contaminated soils was about twice that of NPK-treated soil. The initial microbial biomass-C and estimates of total bacterial numbers by acridine orange direct count were significantly (P 〈 0.05) greater in the FYM-treated soil compared with the NPK-treated and the most contaminated soils. Total phospholipid fatty acid (PLFA) concentration (another measure of biomass) was significantly greater in the FYM-treated soil compared with either the low or high metal-contaminated soils, both of which contained similar PLFA concentrations. In the metal-contaminated soils, in contrast, fluorescent Pseudomonas counts, as a percentage of total plate counts, were at least 1.5 times greater than in the uncontaminated soils. The concentrations of these microbial parameters were significantly (P 〈 0.05) less in the NPK soil than in all the other treatments. Biomass-C as a percentage of organic-C was also significantly (P 〈 0.05) greater in the uncontaminated soils compared with the metal-contaminated soils. Biomass specific respiration rates in the metal-contaminated soils were c. 1.5 times those in the FYM-treated soil. In the metal-contaminated soils, the concentration of mono-unsaturated and hydroxy-fatty acids (derived from phospholipids), and lipopolysaccharide hydroxy-fatty acids (all indicative of Gram-negative bacteria) were significantly (P 〈 0.05) greater than branched fatty acids (indicative of Gram-positive bacteria). Furthermore, Gram-negative counts were 62–68% greater than Gram-positive counts in the metal-contaminated soils. Branched fatty acid concentration was significantly (P 〈 0.05) greater in the FYM-treated soil than in the metal-contaminated soils. Gram-positive counts were also 63% greater than Gram-negative counts in the FYM-treated soil. We found that effects of the relatively small heavy metal concentration caused measurable decreases in soil microbial biomass-C concentrations, acridine orange direct counts and Gram-positive counts. There were also increases in biomass specific respiration rates, and the microbial community had changed substantially, nearly 40 years after the metal inputs ceased. We conclude that, at the very least, the current EU permitted limits for heavy metals in agricultural soils should not be relaxed.